In recent years, macromolecules which have been under intense research include polymers having polymerizable functional groups (including oligomers), and by means of introducing branches into copolymers, graft copolymers can be obtained wherein the length and number of branches are controlled [for reference, see Yuya Yamashita, Makuro-monoma no kagaku to kogyo Macromonomer Chemistry and Engineering, I.P.C (1989); Yuji Kawakami, Macromolecules, Vol. 37, p. 264 (1988), and Yoshiki Nakazo, Macromolecules, Vol. 39, p. 452 (1990)).
Most known macromonomers contain vinyl phenyl groups, acryloyl groups or methacryloyl groups as terminal polymerizing groups, and thus are mainly used for chain-extension polymerization. On the one hand, substances containing terminal diol, dicarboxylic acid, dicarboxylic acid ester, diamine, phenol groups, etc., have been documented (refer to Tezuka et al., Polymer, Vol. 30, p. 553 (1989); Tezuka et al., Macromolecules, Vol. 24, p. 122 (1991); Kawakami et al., Polym. Bull., Vol. 25, p. 521 (1991); Ogawa et al., Japanese Kokai Patent Application No. Hei 1-132634; Nagase et al., Makromol. Chem., Rapid. Commun., Vol. 11, p. 185 (1990); Nagase et al., Japanese Kokai Patent Application No. Hei 1-185327 and K. M. Snow et al., CAP-2,025,289, Jun. 23, 1991. However, organopolysiloxanes having bifunctional biphenyl groups as polymerizing groups and manufacturing methods thereof are not yet known.
Aromatic group polymers such as aromatic polyesters, aromatic polyamide (aramide), and aromatic polyimide are becoming increasingly important high performance polymer materials because of their high mechanical strength, heat resistance, solvent resistance, etc. (for reference, see Kobunshi Kakkai [Polymer Society], Koseino Houkouzokukei Kobunshi Zaiyo High Performance Aromatic Group Polymer Materials, Maruzen (1990)). However, in comparison to conventional flexible polymers, these rigid chain polymers lack solubility in solvents, and the melting point is high and they are difficult to process. As a result, industrial development and application of the materials was just begun in recent years.
As a method of improving the solubility and reducing the melting point of these aromatic group rigid chain polymers, introduction of flexible polymer side chains has been suggested (for reference, see M. Ballauff, Angew. Chem. Int. Ed. Engl., volume 28, page 253 (1989)). For the purpose described above, aromatic polyesters having alkyl and alkyloxy side chains, or alkyl groups bonded through an ester bond (R. W. Lenz et al., Eur. Polym. J., Volume 19, page 1,043 (1983), M. Ballauff, Makromol. Chem., Rapid Commun., Volume 7, page 407 (1986), B. R. Harkness et al., Macromolecules, Volume 24, page 6,759 (1991), etc.), aromatic polyesters having a polystyrene side chain (T. Heitz et al., Makromoi. Chem., Volume 190, page 3,295 (1989)), aromatic polymide having an alkyloxy side chains (M. Ballauff et al., Makromol. Chem., Volume 188, page 2,865 (1987)), etc., were reported. Also, for the purpose of producing a separation film material, an example where a polysiloxane side chain is introduced to a semirigid aromatic polyimide has been reported (Nagase et al., Makromol. Chem., Volume 193, page 1,509 (1992), etc.). However, an aromatic polyimide having an organopolysiloxane side chain and the unit based on diamine monomer bonded with its side chain comprised of a biphenyl group or a copolymer thereof is not known.